This proposal describes the application of a bead-based microarray platform for the rapid and simultaneous screening of multiple allergies. With increasing costs of medical care, rapid tests, which allow multiplexed screening of disease conditions in many samples simultaneously, will be invaluable. Allergies will be screened using the same basic immunoassay format currently employed in allergy testing. The innovation lies in adapting existing solid-phase immunoassay methods to the Sentrix/Tm BeadArray/Tm platform and in multiplexing and miniaturizing the assays. In the R21 Phase, using peanut allergy as a model system for proof of concept, peptide microarrays will be developed for screening peanut allergen-specific IgE binding, using known peanut allergen peptide epitopes. The peptide microarray development will avail of the available ability to sythesize large numbers of different peptides in a short time. Chemistry techniques for conjugating peptides with paired encoding oligonucleotides to beads have been deduced and will be further optimized. The plan for the R33 Phase of this project is to develop methodology on the Sentrix platform to screen multiple food allergies at the same time, including cow's milk, peanut, egg white and soy. Optimization of the multiplexed food allergies will be done to ensure quantitative assays with high reproducibility, precision and accuracy.